I doubt any hobby stores are open, but they'd probably have some modeler magazines for ideas & techniques.
Then again, that info might be on the web nowadays.
If you have a place near you that does paint dipping, something like a patina finish maybe ?
Heck, if it's molded in a color, maybe just polish that and it'd be like a promo.
Nothing wrong with the primer & black gelcoat idea, either.